Bicycle-brake.



O 0 m r p A d .8 m e t a P .E TK TA R B E u Y m B 6 4 6 4 6 0 N (Application filed July 18, 1899.)

2 Sheets-Sheet I.

(No Model.)

INVENTOR 11 FM B) ATTORNEY.

WITNESSES 2. {Km

NITED STATES P TENT OFFICE.

PHILIP W. PRATT, OF SAN FRANCISCO, CALIFORNIA.

BICYCLE-BRAKE.

SPECIFICATION forming part of Letters Patent No. 646,546, dated Apri 3,

I 7 Application filed July 18,1899. Serial No. 724,297. (No model.)

To all z'zihom it may concern-.-

Beitknown that I, PHILIP W.:PBATT, a citizen of the United States, residing at San Francisco, in the county of San Francisco and State of California, have invented certain new and useful Improvements in Bicycle-Brakes, of which the following is a specification.

My invention relates to improvements in.

retard the rotary motion thereof.

In the accompanying drawings, Figure l is a side elevation of a portion of a bicycle pro-' vided with my improvement. Fig.2 is a similar view of the same with the brake set. Fig. 3 is an enlarged side view of the brake proper. Fig. 4 is a front view thereof. Fig. 5 is a vertical section giving a rear view of the braking-rollers. Fig. 6 isa substantiallyhorizontal section through the line 6 6 of Fig. 4. Fig. 7 is a side elevation of a modified form of the device, the'nearer roller being removed.' Fig. Sis a similar view with the brake set. Fig. 9 is a front view. Fig. 10 is a horizontal section, and Fig. 11 isa similar view with the brake set.

1 represents the brake-lever, fulcrumed in the usual manner upon the handle-bar and attached to the brake-stem 2, on the lower end of which is secured by the set-screw 3 the tube 4, having bearings 5 in a gooseneck 6, the arms 7 of which are clamped, as at 8, on -the fork of the front wheel. In the lower end of said tube 4 is secured by a set-screw 10 the rod 11, in the lower end of which is screwed the pivot 12, upon which, between the bottom 'of the rod 11 and the head 13 of said pivot, are pivoted the collars 14 15, the lower collar 14 extending upward to form a segmental neck 16 around the rod 11 and also For this purpose I have providedv around the collar 15, and the upper collar having a similar u pwardly-extending neck 17 and a downwardly-extending segmental neck 18 around the collar 14'. From said collars extend downwardly, but in the plane perpendicular to the direction of motion of the adjacent portion of the tire, the axles 20 of friction-rollers 21, and from said roller-axes being in said perpendicular plane when first brought into contact with the tire it follows that they then roll freely with said tire and exert an inappreciable retardation thereon;

but as the brake-ste1n is still f u rther depressed antifriction-rollers 23, carried on arms 24, extending rearwardly from the necks 16 17, move along the downwardly-diverging faces of a wedge 25, extending from a cross-piece connecting the arms 7 of the gooseneck. By the consequent spreading of the arms 24 the'axles 20 are moved into a forward direction and the rollers no longer move in harmony with the tire, but crosswise or at variance therewith, and exert a retarding effect on the tire. When the pressure is released,

a spring around the tube 4 raises the brakehandle, and a spring 31, having its ends se cured on pins 32, projecting from the necks 16 17, throws said necksand the friction-rollers backward into their normal positions.

In the modification of the invention shown in Figs. 7 to 11 the gooseneck 6 has a forward extension or nose 40, to which is pivoted an 1 arm 41, extending rearwardly and having at its rear end the downwardly-diverging axles 20, carrying rollers 21. Said arm 41 is slotted, as at 42, and the lower end of said rod 11 is loosely pivoted in said slot. Normally the axles 20 extend slightly behind the plane perpendicular to the direction of motion of the tire; but when the brake-stemis depressed the arm 41 swings downwardly and forwardly, so that said axles are in said perpendicular plane when the rollers first come into contact with the tire, and the rollers roll freely thereon, and then as the arm 41 swings still more downwardly and forwardly the axles 20 have also a forward inclination, increasing with the setting of the brake, so that when the brake is fully set the rollers roll across the tire in stead of in the same direction. A spring 44, as before, returns the brake to its normal po-. sition when pressure is removed.

I claim 1. In a brake, the combination of rollers, downwardly-extending axles therefor, said axles at the first contact of the rollers with the tire extending in a plane perpendicular to the direction of motion of the latter, and means for moving said axles into a forward direction,whereby said rollers then roll transversely to the motion of the tire, substantially as described.

2. In a brake, the combination of rollers, axles therefor, said axles at the first contact of the rollers with the tire extendingin a plane substantially perpendicular to the adjacent portion of said tire, whereby said rollers then exert an inappreciable retardation thereon, and means for simultaneously pressing said rollers against the tires and changing the direction of the axles so as to become more and PHILIP XV. PRATT.

Witnesses:

FRANCIS M. WRIGHT, CHAs. W. SMYTH. 

